The Hunger Games: Mockingjay -- Part 1 won't hit theaters until November 21, but ET is already giving fans a behind-the-scenes look at the film.

Oscar nominee Julianne Moore joins the cast for the third installment as District 13's President Coin. In newly released images, Moore is nearly unrecognizable in a long gray wig. The 53-year-old actress says she's a long time fan of the series.

"I read all the books," she admitted. "I read them all the way through and I'm like, 'I want to be in this movie' and clearly that was the only part that I could play.'"

Fans of the franchise love the on screen chemistry of the actors, and according to star Liam Hemsworth that chemistry is even stronger off screen.

"There's not a lot of films that you work on where it's this kind of contagious energy and it's, everyone's feeding off each other," Hemsworth, who plays Gale Hawthorne in the films, told ET while promoting The Hunger Games: Catching Fire. "I think that's why our work then, works. It looks good, you know, 'cause we're all there together and feeding off each other."

Jennifer Lawrence is back as Katniss Everdeen and Josh Hutcherson returns as Peeta Mellark in the next installment.

Check out the video to see how Julianne Moore felt being the newbie on set of The Hunger Games: Mockingjay – Part 1.